This invention relates to metal connectors, methods of manufacturing metal connectors, and machines for manufacturing metal connectors, and more particularly to a method of manufacturing a metal connector plate by use of die or dies of a different pattern and variable actuating device of the sheet metal feed mechanism for use in prefabricated wooden structures, such as roof trusses, floor joists, and the like.
In the past, there have been various types of metal connector plates used to hold wooden members in adjoining relation. By way of example is U.S. Pat. No. 3,377,905, in which a connector plate is illustrated. The connector plate has a multiplicity of teeth extending transversely outwardly from the plate. Each tooth has a base portion and a tip portion of substantially lesser width than the base portion. The opposed edges of each portion are generally parallel with one edge of the tip portion being a continuation of one edge of the base portion. These teeth may be oriented in rows parallel to the transverse mid-line of the plate with the number of teeth per row providing the plate itself with a particular tensile strength. As shown the first row of teeth on each side of the mid-line or mid-portion has lesser teeth than the more remote row or rows. The teeth may also preferably be located in columns parallel to, and on each side of, the longitudinal medial portion of the plate.
Another example is shown in U.S. Pat. No. 3,494,645 in which a high sectioned splice plate and joint therewith is illustrated. The plate has a plurality of nail-like teeth struck therefrom for embedment in a pair of butting wooden members to form a structural joint. The plate has an enlarged band of metal along the opposite lateral edges in which no teeth are struck and has a limited number of teeth across a given cross-section whereby the moment of inertia, cross-section and overall effect of that section of the plate are increased. The plate further approaching a minimum length to width ratio so as to provide a sufficient number of teeth to carry tensile loadings.
The present invention provides a die and variable actuating device to manufacture a new and improved metal connector plate to a desired pattern. The plate is manufactured such that the cumulative tooth holding power of the plate teeth in each column generally increases when advancing to each successive column away from the center line as more teeth are added in the cross-section, in opposite directions from the transverse center line and the plate tearing value remains approximately the same as the plate tearing value in the first column each side of the transverse center line.